The present invention relates to new uracil derivatives and processes for preparing same. More particularly, the present invention relates to new 1-acyloxymethyl-5-fluorouracil derivatives and 1,3-bis(acyloxymethyl)-5-fluorouracil derivatives and processes for preparing same.
Heretofore, various kinds of uracil derivatives have been developed as anti-tumor agents. Concerning 1acyloxymethyl-5-fluorouracil derivatives, however, no study have been made by any person other than the present inventors. More precisely, 1-acetoxymethyl-5-fluorouracil, 1-pivaloyloxymethyl-5-fluorouracil and 1-palmitoyloxymethyl-5-fluorouracil were developed for the first time by the present inventors as a new class of uracil derivatives and disclosed in Japanese Patent Prov. Publn. No. 98280/76.
However, the above mentioned 1-acyloxymethyl-5-fluorouracil derivatives are disadvantageous in that 1-acetoxymethyl-5-fluorouracil shows high toxicity, 1-pivaloyloxymethyl-5-fluorouracil weak anti-tumor activity and 1-palmitoyloxymethyl-5-fluorouracil poor absorbability in living body. Thus, there is still a great demand for developing new anti-tumor agents of 1-acyloxymethyl-5-fluorouracil series, which are strong in anti-tumor activity and possess good absorbability in living body with very low toxicity.